It looks like a lean jetting cond. or higher octane fuel needed or a combination of both. If your running higher comp. in the engine you need to run higher octane fuel. A 2 stroke engine will melt a cast piston if the jetting is lean & using a lower octane than what the motor was set up for.

It looks like a lean jetting cond. or higher octane fuel needed or a combination of both. If your running higher comp. in the engine you need to run higher octane fuel. A 2 stroke engine will melt a cast piston if the jetting is lean & using a lower octane than what the motor was set up for.